We have adopted this diet for ourselves and our families, for health and well-being reasons. And we continue to eat this way because we love what we eat.

As physicians, we are concerned when we see misinformation circulating in the media, especially when it comes from health-care professionals. Therefore, we would like to rectify some points raised recently by a few nutritionists and dietitians in a letter of opinion published in a daily newspaper in Quebec.

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Not a 'fad diet'

First, the low-carbohydrate, high-fat diet (LCHF) is not a "fad diet." It's a way of eating that is as old as the world. Human beings evolved by eating this way for hundreds of thousands of years. In fact, humans have only been eating an abnormally high quantity of carbohydrates (bread, pasta, potatoes, rice, fruits and sweets) for about four decades.

The "restrictive" nature of this diet is often cited as a reason not to offer it to patients. It will supposedly be so difficult to sustain it that the majority of people will give up in the short or medium term.

People who choose to be vegetarians face restrictions and make choices for their own health, just like people who are intolerant to gluten. Let's not forget that people who are following a low-fat diet, the fad diet of the last few decades, also face many food restrictions, such as: avoiding whole dairy products, fatty cheeses, full cream, butter, eggs and certain cuts of meat. When it comes to health, we all make choices. The low-carb diet is no exception, and is not any more restrictive than other diets. It deserves to be offered.

The main objective of LCHF isn't rapid weight loss. LCHF is a way of eating, a way of life.

Following a low-carbohydrate diet often makes counting grams or calories unnecessary. This practice, which is so common in many approaches in the field of nutrition, can trigger an eating disorder. Rather, patients are taught to listen to their bodies, and to stop eating when they feel full. Weight loss has been shown to be more effective with low-carb diets than with the standard low-fat diet, and this occurs while feeling satiated.

One must understand that in order to get the energy required to properly function, assuming protein intakes are constant, carbohydrates must be increased if fats are drastically reduced. We favour an approach that is lower in carbohydrates and higher in natural fats than the current dietary guidelines recommend. Natural fats are present in butter, cream, cuts of whole meat, fatty cheeses, olive oil, avocados and coconut, for example.

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The experience of thousands of doctors and other health professionals

Our personal and clinical experience shows that this diet is more varied, tasty and satiating than the low-fat diet proposed by the Canadian Food Guide. We are thousands of doctors across the country and around the world who have adopted this way of eating for ourselves and our families, for health and well-being reasons. And we continue to eat this way in part because we love what we eat.

The main objective of LCHF isn't rapid weight loss. LCHF is a way of eating, a way of life. Weight loss is one of the side-effects of this way of eating, and it is not always rapid. We offer this diet to our patients because it can help reverse several lifestyle chronic diseases, such as type 2 diabetes, metabolic syndrome, chronic pain and chronic fatigue, hypertension, etc.

The human body mainly draws its energy from ingested carbohydrates, protein and lipids. However, carbohydrates are not essential for providing fuel. Lipids can play this role in the human body, often more efficiently. There are essential fatty acids and essential amino acids. But there are no essential carbohydrates. According to the National Academies of Science, Engineering and Medicine (U.S.), "The lower limit of carbohydrates compatible with life is apparently zero, provided that adequate amounts of protein and fat are consumed."

One of the most common myths is that carbohydrates are essential to brain function. This is false. Certain parts of the brain need glucose, possibly around 130 grams per day, but that glucose does not need to come from ingested carbohydrates. The liver can effortlessly produce the required glucose from protein and fat: it is called gluconeogenesis. However, reducing carbohydrate intake to 130 gram per day would already be a step in the right direction over what many patients are currently eating, and would correspond to a liberal form of low-carb/LCHF, resulting in real health benefits for the majority of patients.

The pleasure of eating is important, indeed, but the pleasure of living a healthy life is even more important in our view.

It is true that carbohydrates can contribute to the pleasure of eating, but they are not essential to make food tasty. That being said, a well-designed low-carb diet allows for plenty of high-quality whole food sources of carbohydrates, such as vegetables, whole milk products, nuts, seeds, berries, legumes and smaller amounts of whole grains. People with diabetes can choose to eat less of them, while others without metabolic problems may choose to eat more. It's a choice. The pleasure of eating is important, indeed, but the pleasure of living a healthy life is even more important in our view.

Let's briefly mention that people who adopt a low-carb diet very frequently report a significant reduction or disappearance of their IBS symptoms, including less cramps, flatulence and bloating. We believe that it is likely, therefore, that their microbiota (intestinal flora) improves.

Deficiencies? Yet another myth!

Let us also mention that a well-designed, whole food low-carb diet does not create nutrient deficiencies. In fact, it is quite the opposite. The preferred foods contain large amounts of fibre, minerals and vitamins, including fat-soluble vitamins often missing in low-fat diets. There are no useful nutrients in enriched grain products that are not found naturally and in sufficient quantities in meat, eggs, green vegetables and nuts. Most grain products readily available today, such as bread and pasta, are processed and sometimes ultra-processed. We prefer unprocessed foods.

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Canada's Food Guide: where is the evidence?

We believe that chronic nutritional diseases are mostly caused by an excess of processed foods; when we suggest lowering carbohydrates to help reverse these chronic diseases, we are often told to stop looking for the guilty nutrient and rather aim for balance. This must mean that those critics think it is better to eat a "balanced diet," as proposed by Canada's Food Guide.

However, this guide, in its current state, is not at all balanced. It puts too much emphasis on relatively nutrient-poor carbohydrates, including processed and ultra-processed carbohydrates, and not enough on lipids. These dietary recommendations have actually never been tested in a population to see if they were indeed good for our health and are not supported by any scientificstudies. Since issuing these guidelines in both the U.S. and Canada, and specifically since increasing the recommended servings of carbohydrates, it must be noted that the rates of obesity, type 2 diabetes and cardiovascular diseases, to name only these three chronic diseases, have exploded. Could it be that our Guide's recommendations are making us sick?

It is true that there is a difference between processed foods rich in carbohydrates and natural whole foods rich in carbohydrates, such as fruits. But it would be simplistic to believe that because something is natural or called "whole grain," like a banana or "whole wheat bread," that we cannot develop health problems as long as we eat them in the quantities recommended by the guide. Humans evolved as hunter-gatherers, feeding almost exclusively on meats and vegetables. Although fruits are natural, humans ate very small amounts, mainly in the form of berries, and not throughout the year. It was the occasional candy from nature, as opposed to the year-round summer buffet that exists in our grocery stores now.

Despite whether sugar comes from a banana, a soft drink or a slice of bread, it will generally have the same effect on blood sugar, particularly in diabetics. The blood sugar level will rise. When sugar rises, the pancreas secretes insulin to decrease the amount of sugar in the blood. This insulin can also come from an injection prescribed by the doctor.

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Dying of a heart attack with a normal blood sugar level

It is now thought that an excess of insulin in the body, due to an excess intake of sugar, causes insulin resistance in the long term: the cells respond less and less to the insulin signal. Having a fatty liver can also worsen insulin resistance and diabetes. That promotes weight gain, high blood pressure, and inflammation. In the long-term, the risk of cardiovascular disease, blindness, kidney failure, erectile dysfunction, etc., are increased. Most people do not know that even perfect control of blood glucose with intensive drug treatment might not necessarily prevent the occurrence of cardiovascular disease in diabetics (ACCORD and ADVANCE studies). Why? Because the problem has not been treated at the source; insulin resistance and hyperinsulinemia have not been addressed. Dying of a heart attack with a normal blood sugar level is not the goal, is it?

For someone with diabetes, would it not make more sense to significantly reduce their sugar intakes rather than take drugs to manage the excess of sugar in the blood? Wouldn't it be better for that person to manage their type 2 diabetes without medication or insulin, with a low carbohydrate diet?

Many of us doctors want to be able to work with nutritionists and dieticians to teach patients to eat less carbs, so that we can reduce or eliminate a good part of their medications, and help them to not just manage their chronic diseases caused by lifestyle choices, but to actually help reverse them.